1. Field of the Invention
The present invention relates to an apparatus for lining pipe which renovates the inside of an underground damaged pipe.
2. Discussion of the Background
In order to renovate a damaged pipe buried in the ground, a plastic strip which has joint portions along both side edges is spirally wound to line the inside of the underground damaged pipe. A plastic strip is supplied to the underground damaged pipe and spirally wound with an apparatus to join the plastic strip to itself at joint portions thereof.
According to Japanese patent publication Nos. 1998-274389, 2001-138398, and 2009-144744, an apparatus for lining pipe is arranged in an underground damaged pipe, and the plastic strip is pulled out from the storage drum and supplied to the apparatus to line the damaged pipe. Subsequently, the winding apparatus is rotated inside the underground damaged pipe, and the plastic strip is wound spirally. Therefore with the winding apparatus, the joint portions of adjacent portions of the plastic strip are interlocked as the plastic strip is wound.
The winding apparatus is equipped with a rail which has rigidity and holds its form. The forming frame can move the perimeter of the rail through a guide, and the lining of an underground damaged pipe having various cross-sectional shapes is formed. The rail has a form similar to the cross-sectional form of the underground damaged pipe, and specifies the form of the forming frame and the lining pipe. A plurality of connectors 92 are installed in apparatus 91 between a forming frame 93 and rails 94, as shown in FIG. 13. The connectors 92 follow the track of the forming frame 93 along with the perimeter of the rail 94.
As shown in FIG. 14, the rail 94 forms a channel which contains the roller 95 with connector 92. Winding a plastic strip 100 spirally requires a heavy load in the direction of a longitudinal axis be applied to the forming frame 93 and the connector 92. The connector 92 is positioned in the rail 94 and moves on a longitudinal axis (the axis of N in FIG. 14) in response to the load. The rollers 95 are the width of opening 941, are on the inside of the rail 94, and permit the connector 92 to move along the longitudinal axis.
Since there is a possibility of spoiling the dimensional accuracy of the lining pipe when the connector 92 moves too much along the longitudinal axis (N) into the rail 94, it is necessary to regulate movement of a roller 95 within a limited range. Therefore, a guide part 96, in alignment with the longitudinal axis (N), is attached to the inside of the rail 94.
As shown in FIG. 14, the guide part 96 is fixed in two positions at each end of an inside of the rail 94. The guide part 96 has a size corresponding to the size of the outside of the roller 95, and is in upper and lower positions inside of the rail 94. The angle part of the outside of the roller 95 hits the guide part 96 of the rail 94 when the roller 95 rotates, thereby restricting the movement of the connector 92 along the longitudinal axis. A bolt-head part 97 projected on the outside of the roller 95 moves between the upper and lower guide parts 96. The rail 94 of the conventional winding apparatus 91 is formed to be thick in order to receive a load through the connector 92.
The lip part 98 faces the forming frame 93, and is prepared along a longitudinal axis. A full load acts on the pipe bottom side of the underground damaged pipe 7 through a roller 95 at the lip part 98. Therefore, the lip part 98 is thickly reinforced to support the roller 95. As a result, the rail 94 is needed to be formed from thick materials making the rail 94 and its associated parts very heavy. It is hard to assemble a heavy rail 94, and as a result, installation is lengthy. Also, it is difficult to manufacture the rail 94 and the guide part 96 with high precision and thus, manufacturing costs are increased. Further, in the lining pipe process, with the bearing installed inside the roller 95 and the roller 95 contacting the inside of the guide part 96 contained within the rail 94, the roller 95 is easily damaged. In addition, inferior durability of the roller 95 is experienced when a load is applied along the longitudinal axis through the connector 92. Also, exchange and repair of the roller 95 of a bearing portion also takes time and effort.